Hurricane Sandy brought a 14-foot tide of water through the streets of New York City and devastation along the coast of New Jersey in 2012. Over 50 people were killed. FEMA estimated a cost of $70.2 billion, making it at the time the second costliest hurricane is U.S. history. In the seven years since, the recovery has progressed slowly. Many homeowners have struggled to navigate a complex and inadequate system of government aid and insurance money.

In the wake of Sandy, many have considered the future climate change-driven risks to the city, including rising seas and the potential for more destructive storms. Proposals to mitigate these dangers have ranged from wetland restoration, buy-out programs, and oyster reefs that could protect New York City from flooding. In a nation that loves big infrastructure projects, one proposal has captured significant attention: building a six-mile long barrier to protect the city. The idea has been discussed for years but early last week The New York Times wrote an article confirming that the barrier is one of five projects being considered by the Army Corps of Engineers.

Presumably it was this article that led President Trump to tweet his own plan for protecting the largest city in America: "mops and buckets."

A massive 200 Billion Dollar Sea Wall, built around New York to protect it from rare storms, is a costly, foolish & environmentally unfriendly idea that, when needed, probably won’t work anyway. It will also look terrible. Sorry, you’ll just have to get your mops & buckets ready!

There's plenty to parse in the tweet. The $200 billion price tag is an exaggeration from the $119 billion reported by the Times. He denies the city's increasing flood risk. And concerns about the aesthetics of a wall are intriguing given his propensity for other walls, not just at the U.S.-Mexico border but also a sea wall to protect his golf course in Ireland.

This doesn't mean there aren't valid and very serious questions about the most effective and just approach to protecting New York and New Jersey from flooding. But these serious questions deserve to be answered with serious solutions. "Mops & buckets" is dismissive and reminiscent of the president throwing paper towels at Puerto Ricans in the wake of Hurricane Maria. It is also a dangerous return to the antiquated, reactive approach historically taken to emergency management.

For most of U.S. history, we have done relatively little to prevent disasters from happening. Despite decades of pleas from scholars and emergency management practitioners, we wait for disasters to hit and then we deal with the consequences. Instead of putting more effort and resources into hazard mitigation and preparedness, to prevent disasters from happening in the first place and to ready communities for those we can't, we devote ourselves to response and recovery.

Now, as our national risk changes in the face of the climate crisis there is even more value in implementing mitigation measures before a disaster happens. A frequently cited 2018 report from the National Institute of Building Sciences found that for every $1 the federal government spends on hazard mitigation, $6 is saved in response and recovery. Doing mitigation pre-disaster isn't just financially smart, it also saves lives. The same report found that the implementation of just some mitigation strategies could "prevent 600 deaths, 1 million nonfatal injuries and 4,000 cases of post-traumatic stress disorder." These findings have been echoed in more blunt statements like that from New York City Mayor de Blasio who tweeted in response to Trump, "Your climate denial isn't just dangerous to those you've sworn to protect — it's deadly."

While certainly there is a stark difference between Democrats and Republicans on issues of emergency management, there is still a disconnect between what national Democratic leaders are saying and doing, as a whole, and what scientists expect our risks to be and what frontline communities are already experiencing.

During a September town hall on climate change hosted by CNN, a member of the audience shared that her daughter had been killed during Superstorm Sandy. She asked Joe Biden what specific policies he would implement in his first year as president to "mitigate the impact of climate change." His answer was about efficiency standards for appliances and charging stations, conflating the prevention of disasters with taking action on climate change. This has been the dominant narrative among all the Democratic presidential candidates. It's true that taking action on climate change is important for reducing the number of future disasters, but it's also true that we can't prevent all future disasters just by taking action on climate change.

Discussion of emergency management policy has been largely absent among the democratic debates, forums, and climate plans, despite the continual usage of recent disasters to frame conversations about climate policy. When candidates have been asked about their plans for communities experiencing disasters, a frequent answer is "managed retreat." But there is little to no explanation about what this entails. This was reiterated at the most recent debate where candidates were asked what to do about flooded farms and factories in the Midwest.

A key challenge of disaster mitigation is that for efforts to be effective they must be taken pre-disaster. This requires an accurate understanding of our risk in a changing climate and requires politicians to think about the future. It means making investments now, even though the benefits may not be felt for decades.

It's estimated that the six-mile barrier proposed for New York City will take 25 years to build, although anyone with experience working on large scale infrastructure projects is sure to tell you it will take longer. Following in the footsteps of the levee system in New Orleans, the MOSE barrier in Venice, and the flood infrastructure projects in the Netherlands, we know there are serious environmental consequences, big budgets, and the risk that it will not work. We need to act quickly because time is not on our side.

The solution to this challenge though is not to ready our mops and buckets, but rather to keep searching for the approaches that are effective, efficient, and just.